TAS6424E-Q1: Output noise floor

miyuki.fukumoto

Prodigy 60 points

Part Number: TAS6424E-Q1
Other Parts Discussed in Thread: TAS6424E

Hello everyone,

I would like to ask for advice.

① Start AMP, change to PLAY mode and input 0 data. At this time, the noise is measured using the AP.

② Input audio data (Not 0 data) without changing the operating status of AMP.

③ Input 0 data again and measure the noise. At this time, compared to ①, the noise increased by about 10~30uV.

④ Turn off the power and restart it to return to the state of ①.

If you know why this happens, please let me know.

Also, are there any register settings other than the gain level settings and PVDD voltage that affect the noise level?

Best Regards,
Fukumoto

8 months ago

0 Gregg Scott 8 months ago

TI__Mastermind 37015 points

Fukumoto-san,

Please wait for 20 seconds for the DAC to settle and the noise will be back down.

Regards,
Gregg Scott

0 miyuki.fukumoto 8 months ago in reply to Gregg Scott

Prodigy 60 points

Thank you for your reply!
I tried waiting for about 2 minutes, but I didn't see any reduction in the noise level.
Am I misunderstanding something?

0 Shadow He 8 months ago in reply to miyuki.fukumoto

TI__Mastermind 36810 points

Hi Miyuki

When TAS6424E firstly set to PLAY but no audio, the internal DAC still not start working, so the total noise will be a little smaller. So you find 10~30uV noise change is normal. Usually after this change, the total noise should be still within datasheet Spec.